Calibre see my A500 and start to get the book list and it takes hours to do. is there any way to config calibre to only check a few dir like ebook,LumiBooks, Kindle and not the hold device?

I limit the directories scanned by connecting to calibre wirelessly via the Calibre Companion android app. I have about 2050 books on my device and when I connect to calibre it takes around 80 seconds to scan the directories specified by me and update the metadata on all 2050 existing books on my device. The app also lets me put ePubs, mobi, pdf files etc.. in directories I designate.

When connecting to MTP devices such as the Kindle Fire HD or the Nook HD, speed up the process by ignoring some folders.

calibre will now ignore folders for music, video, pictures, etc. when scanning the device. This can substantially speed up the connection process if you have thousands of non-ebook files on the device. The list of folders to be ignored can be customized by right clicking on the device icon in calibre and selecting 'Configure this device'.